The present invention relates to an injectable homogeneous aqueous solution of chitosan containing, in a physiologically acceptable medium, between 0.1 and 4.5% by weight of a chitosan having a degree of acetylation less than 20% and a weight average molecular mass of between 100,000 and 1,500,000 g/mol, said solution having a pH greater than or equal to 6.2, and advantageously between 6.2 and 7.2, said solution not containing any chitosan having a degree of acetylation greater than 20%, said solution being liquid and homogeneous at ambient temperature. The invention also relates to an aqueous solution such as previously described, characterised in that it can be prepared by a method comprising at least the following steps:—dissolving the chitosan in water by adding acid, such as a weak acid, said weak acid being advantageously chosen from the group consisting of acetic acid, glycolic acid, lactic acid, glutamic acid, and the mixtures of same, andreadjusting the pH by dialysis, preferably at ambient temperature, in order to obtain an aqueous solution having a pH greater than or equal to 6.2, advantageously between 6.2 and 7.2, and preferably between 6.25 and 7.1.
